TY - JOUR

T1 - Petrography and geochemical analysis of Arctic ikaite pseudomorphs from Utqiaġvik (Barrow), Alaska

AU - Schultz, Bo P.

AU - Huggett, Jennifer M.

AU - Kennedy, George L.

AU - Burger, Paul

AU - Friis, Henrik

AU - Jensen, Anne M.

AU - Kanstrup, Marie

AU - Bernasconi, Stefano M.

AU - Thibault, Nicolas

AU - Ullmann, Clemens V.

AU - Vickers, Madeleine L.

N1 - Funding Information: Marincovich for the opportunity to collaborate in their Alaskan field studies in  and 堀 Funding was provided for this study by the European Commission, Horizon 2020 (ICECAP; grant no. 缀 to M 堀㸃堀 Vickers 唀 and from the Research Council of Norway through the Centres of Excellence funding scheme 唀 project number 堀 The Research Council of Norway is acknowledged for support to the Goldschmidt ?aboratory national infrastructure 縁褁谁紁椁ḁခ騀 number 缃唀 and we thank Siri Simonsen for use and running of the SEM at the University of Oslo. Lastly, we thank the two anonymous reviewers for their constructive comments that have helped to improve the final manuscript 堀 Thanks to Iñupiat Heritage Center and Army Corps of Engineers for informations 唀 and to all Iñupiat inhabitants who has helped improving this paper. Profound thanks to Norwegian Journal of Geology and coauthors, specially project holder Madeleine Vickers for making this a much better paper ? Funding Information: G. L. Kennedy thanks USGS colleagues D. M. Hopkins and L. N. Marincovich for the opportunity to collaborate in their Alaskan field studies in 1981 and 1983. Funding was provided for this study by the European Commission, Horizon 2020 (ICECAP; grant no. 101024218) to M.L. Vickers, and from the Research Council of Norway through the Centres of Excellence funding scheme, project number 223272. The Research Council of Norway is acknowledged for support to the Goldschmidt Laboratory national infrastructure (project number 295894), and we thank Siri Simonsen for use and running of the SEM at the University of Oslo. Lastly, we thank the two anonymous reviewers for their constructive comments that have helped to improve the final manuscript. Thanks to Iñupiat Heritage Center and Army Corps of Engineers for informations, and to all Iñupiat inhabitants who has helped improving this paper. Profound thanks to Norwegian Journal of Geology and coauthors, specially project holder Madeleine Vickers for making this a much better paper. Publisher Copyright: © the authors.

PY - 2023

Y1 - 2023

N2 - y Ikaite and pseudomorphs thereafter (“glendonites”) are a potentially powerful tool for palaeoclimatic studies, as a low-temperature proxy. However, much uncertainty still surrounds the drivers of ikaite formation, in particular prerequisite thermal and chemical conditions. Furthermore, the ikaite to glendonite transformation is not fully understood, and it was unclear which calcite phases in glendonites were ikaite-derived and which were later diagenetic calcites. This leads to difficulties in choosing which phase to analyse in order to reconstruct the original ikaite growth environmental conditions. Petrographic examination of air-transformed ikaite from the Isatkoak Lagoon in Utqiaġvik, Alaska, confirms that both ’Type I’ and ’Type II’ calcite phases seen in glendonites are directly derived from ikaite breakdown and not from secondary sources. Clumped isotope temperature reconstructions for transformed ikaites from Utqiaġvik, and comparison to Recent glendonites from the White Sea, Russia, confirm that clumped isotope thermometry may be used to reconstruct ikaite growth temperatures, whilst stable isotopes and minor elemental analysis reveal that a range of geochemical conditions characterise ikaite growth sites.

AB - y Ikaite and pseudomorphs thereafter (“glendonites”) are a potentially powerful tool for palaeoclimatic studies, as a low-temperature proxy. However, much uncertainty still surrounds the drivers of ikaite formation, in particular prerequisite thermal and chemical conditions. Furthermore, the ikaite to glendonite transformation is not fully understood, and it was unclear which calcite phases in glendonites were ikaite-derived and which were later diagenetic calcites. This leads to difficulties in choosing which phase to analyse in order to reconstruct the original ikaite growth environmental conditions. Petrographic examination of air-transformed ikaite from the Isatkoak Lagoon in Utqiaġvik, Alaska, confirms that both ’Type I’ and ’Type II’ calcite phases seen in glendonites are directly derived from ikaite breakdown and not from secondary sources. Clumped isotope temperature reconstructions for transformed ikaites from Utqiaġvik, and comparison to Recent glendonites from the White Sea, Russia, confirm that clumped isotope thermometry may be used to reconstruct ikaite growth temperatures, whilst stable isotopes and minor elemental analysis reveal that a range of geochemical conditions characterise ikaite growth sites.

KW - Coastal

KW - Glendonite

KW - Holocene

KW - Ikaite

KW - Isotopes

KW - Petrology

U2 - 10.17850/njg103-1-3

DO - 10.17850/njg103-1-3

M3 - Journal article

AN - SCOPUS:85149260805

VL - 103

JO - Norwegian Journal of Geology

JF - Norwegian Journal of Geology

SN - 2387-5852

IS - 1

M1 - 202303

ER -